Alert archive / California / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 19, NWS Phoenix, AZ

July 22, 1997Imperial County, California

NWS Phoenix, AZ issued this severe thunderstorm warning at Jul 22, 1997, 6:03 PM PDT for Imperial County, California. It was in force for 62 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 22, 1997, 6:03 PM PDT (01:03 UTC)
Expired
Jul 22, 1997, 7:05 PM PDT
In force
62 min
Issued by
NWS Phoenix, AZ
Area
Whole counties

County Imperial County, CA

The radar

The Yuma radar (KYUX), 90 km from the middle of the area, began a volume at 01:05 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

San Diego, CA (KNKX), launched 00:00Z, 1.1 hours before the alert went out and 173 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, San Diego, CA at 00:00Z on 1997-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, San Diego, CA at 00:00Z on 1997-07-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 30 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
4 J/kg
Mixed-layer CIN
-525 J/kg
Mixed-layer LCL
1453 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
30 m²/s²
0-3 km storm-relative helicity
83 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KPHX 230105 RRA
SVRPHX
CAC025-230205-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
603 PM MST (603 PM PDT) TUE JUL 22 1997

*  SEVERE THUNDERSTORM WARNING FOR
   EASTERN IMPERIAL COUNTY IN SOUTHEASTERN CALIFORNIA

*  UNTIL 705 PM PDT (705 PM MST)

*  SOME LOCATIONS AFFECTED
   WINTERHAVEN...FORT YUMA INDIAN RESERVATION AND OGILBY
 
*  AT 600 PM PDT RADAR INDICATED A SEVERE THUNDERSTORM MOVING INTO
   FAR EASTERN IMPERIAL COUNTY. MOVEMENT WAS TO THE NORTH AT 10 MPH.
   THESE STORMS HAVE A HISTORY OF PRODUCING STRONG GUSTY
   WINDS...SMALL TO MEDIUM SIZED HAIL AND HEAVY RAIN.
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55 MPH...
DESTRUCTIVE *HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN.  FOR YOUR
PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR
HOME OR BUSINESS.

JAH

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, Jul 22, 2:56 PM PDT, 3 hours 7 minutes before
AZZ020>025-CAZ030>033-230130-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
245 PM MST/PDT TUE JUL 22 1997

...SLIGHT RISK FOR SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING OVER PORTIONS OF THE FAR SOUTHEAST CALIFORNIA DESERTS NEAR
IMPERIAL...

SCATTERED THUNDERSTORMS DEVELOPED OVER THE BAJA CALIFORNIA MOUNTAINS
SOUTH OF IMPERIAL AND MEXICALI THIS AFTERNOON.  THESE STORMS WERE
MOVING NORTH TOWARD WESTERN IMPERIAL COUNTY. THERE IS A SLIGHT RISK
OF DAMAGING STRAIGHTLINE WINDS AND LOCALLY HEAVY RAINFALL IN WESTERN
IMPERIAL COUNTY.

THE FAVORED LOCATIONS FOR STRONG THUNDERSTORMS IN WESTERN IMPERIAL
COUNTY ARE FROM THE TOWNS OF HOLTVILLE AND BRAWLEY WESTWARD TO THE
SAN DIEGO COUNTY LINE.  THIS INCLUDES PORTIONS OF INTERSTATE 8 AND
THE SOUTHWESTERN SHORES OF THE SALTON SEA.

....................................................................

THE OUTLOOK AREA INCLUDES THE FOLLOWING COUNTIES...

IN ARIZONA                         IN CALIFORNIA

MARICOPA            YUMA           IMPERIAL
SOUTHERN GILA       LA PAZ         CENTRAL/EASTERN RIVERSIDE
NORTHWEST PINAL

VASQUEZ

The office that day

Everything else NWS Phoenix, AZ issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 22, 7:02 PM PDTFlash Flood WarningPSRRiverside78 min
Jul 22, 7:02 PM PDTSevere Thunderstorm WarningPSRRiverside78 min
Jul 22, 8:01 PM PDTSevere Thunderstorm WarningPSRRiverside74 min

Nearby

Severe Thunderstorm Warnings in California, 1997Every severe thunderstorm warning in 1997

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.